1. Field of the Invention
This invention relates to an improved steam cooker for rice and vegetables and more particularly to such a steam cooker including an improved electric heater unit for boiling water in a reservoir in the cooker.
2. Description of the Prior Art
The popularity of steam cooking utensils for use in the preparation of fresh vegetables, rice and the like has grown rapidly in recent years as the general population has become more conscious of the need for a healthy, well-balanced diet. Steam cookers now available on the market for home use generally employ relatively high wattage electric heaters mounted in the bottom of a water reservoir to quickly generate steam and thereby reduce the time required for cooking. The heaters employed in known steam cookers of this type generally have not been entirely satisfactory, however, for various reasons. For example, heaters having a relatively deep "well" or boiler chamber similar to those employed in electric percolators may quickly heat the relatively small volume of water in the boiler, but can produce relatively violent localized boiling action which may result in excessive water being carried into contact with the food being cooked. Further, since only a relatively small volume of water is in the boiler at any one time, a substantial period may be required to heat all the water in the reservoir to the desired temperature for fast, uniform cooking.
Heating units which employ a larger heating surface in contact with the water in the reservoir are also known. Such units generally employ a large metal heat sink and heat substantially the entire volume of water to or near the boiling point before cooking can commence. Attempts to reduce this startup time by using heater elements of higher capacity (higher wattage) generally result in a higher overshoot temperature which, again, may result in more violent localized boiling action and can result in a shortened life for the heating element.